Driving under influence, particularly with alcohol, is the cause of many injuries and even deaths and thus poses a serious problem to the modern society. Many drunk drivers are chronic alcoholics who knowingly become intoxicated. However, many others drunk drivers are merely social drinkers who did not intend to drive while intoxicated. For example, these people may go to social events with a good intention not to overindulge themselves, but eventually lose track of how many glasses of wine they have enjoyed and become intoxicated. When they leave the social events, they may try to drive the vehicle because their judgment has been impaired by the intoxication. Many accidents may be prevented from happening if drunk drivers are not able to drive while intoxicated.